LCDs are commonly used as display devices for compact electronic apparatuses. Typical LCDs not only provide good quality images with little power consumption, but also are very thin. In general, an LCD includes a liquid crystal panel and a backlight module for illuminating the liquid crystal panel.
The LCD panel needs to be driven by gamma voltages in order to display images. The gamma voltages are provided by an external apparatus. Each gray scale of the images displayed by the LCD panel corresponds to a gamma voltage signal.
The LCD usually further includes a gamma circuit having a gamma correction table for correcting the gamma voltage signals according to a predetermined gamma parameter γ. The gamma parameter γ can be, for example, 2.2. The correction process is generally based on a formula Y=A*Xγ (where A is a constant, X represents a gamma voltage signal, and Y represents a corresponding gray scale). The correction table includes the gamma voltage signals and the corresponding gray scales. However, because different mass manufactured LCDs inevitably have inherent differences, the gamma parameter γ that is preset for a particular LCD model may not be apt for every individual LCD in the batch of LCDs manufactured. That is, for different LCDs in the batch, the actual gray scales displayed may not be the best possible gray scales that can achieve optimum display of images. Thus the gamma correction table may be unable to achieve its intended function in some of these LCDs.
What is needed, therefore, is a method for establishing a gamma correction table for a liquid crystal display which can overcome the above-described deficiencies.